The invention relates to a system for controlling the chemical balance of a body of liquid within a given range, preferably the chlorine and pH balance of a swimming pool.
Many systems have been designed for controlling the chemical balance of a swimming pool and the like. For the most part, simple, inexpensive systems performing this function automatically dispense pre-set amounts of chemicals into the pool at pre-set intervals. They do not sense or respond to the chemical condition of the pool, a condition which will vary dramatically with pool usage, weather, temperature, and other environmental factors. Thus, they easily can cause the chemical balance of the pool to depart considerably from the proper range. The more expensive, elaborate versions of such systems do sense the chemical balance of the pool, and dispense chemicals to maintain the balance of a pool with a given range. However, because of their elaborate nature such systems only are economical for large, heavily used pools.
Maintaining the chemical balance of a swimming pool is quite important. If the chemical balance departs from (drops below) a given range, unsanitary conditions will develop permitting algae and bacteria to grow and contaminate the pool. If such conditions exist for long, they may require the pool to be drained and acid washed. Improperly high chlorine and pH levels can cause eye and skin irritations to swimmers, as well as pipe corrosion or scaling to the recirculating system, giving rise to increased heating costs due largely to the resultant inefficiencies. Improper chemical balance also may waste costly chemicals.
There is a real need for an automatic chemical control system for a swimming pool, one which is relatively simple in construction yet sensitive and durable in operation. Such a system would provide significant safety and a real convenience to the pool owner, reducing his usage of pool chemicals and permitting him to leave the pool unattended for extended periods of time. The system described herein meets these objectives, as well as other objectives which will be apparent to those skilled in the art upon reading the following detailed description.